• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.3
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• pp.155-163
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• 2009

We develop a probability model to evaluate information security investment portfolios. We assume that organizations install portfolios of information security countermeasures to mitigate the damage such as loss of the transaction being processed, damage of hardware and data, etc. A queueing model and Its expected value analysis are used to derive the lost cost of transactions being processed, the replacement cost of hardwares, and the recovery cost of data. The net present value for each portfolio is derived and organizations can select the optimal information security investment portfolio by comparing portfolios.

• Ocean and Polar Research
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• v.24 no.1
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• pp.93-114
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• 2002

Legal regimes of major countries actively involved in wetland programs including USA, Japan, Germany, Netherlands, and Denmark, show that these leading nations have developed their own legal regimes and policies for the conservation and restoration of wetlands since early 1990s. The main feature of their position is to preserve, create and restore wetlands, including tidal flats. However, this approach, so called 'mitigation' policy, is thus far, not a fully established policy but an evolving one. For Korea, there are only a few laws and policies which hint at the importance of creating coastal wetlands as a conservation measure, however, most of those systems only exist as vague provisions which lack any tangible and compulsory implementing procedures and technical guidelines. It seems that it is necessary to strengthen the legal measures for conserving coastal wetlands in Korea including specifying economic assessment methods and funding sources for the creation, restoration and rehabilitation of tidal flats to firmly establish a national wetland mitigation policy.

• Structural Engineering and Mechanics
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• v.49 no.4
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• pp.523-536
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• 2014

Before incorporating the earthquake-resistance design in design standard (1988) in South Korea, most of existing residential buildings were built without having lateral resistance capacity in addition to their structural peculiarity, such as exterior stair ways, exterior elevator room. For these reasons, the demands on retrofitting research for existing buildings arise recently and many retrofitting methods are proposed. These tasks are important to reduce the enormous economic loss and environmental issues. As the main purpose, this study was intended to examine the performance improvement in terms of ductility and strength in the wake of retrofitting and to suggest retrofitting details.

• Wind and Structures
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• v.19 no.6
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• pp.603-621
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• 2014

Past high speed wind events have exposed the vulnerability of the roof systems of existing light-framed wood structures to uplift loading, contributing greatly to economic and human loss. This paper further investigates the behaviour of light-framed wood structures under the uplift loading of a realistic pressure distribution. A three-dimensional finite-element model is first developed to capture the behaviour of a recently completed full-scale experiment. After describing the components used to develop the numerical model, a comparison between the numerical prediction and experimental results in terms of the deflected shape at the roof-to-wall connections is presented to gain confidence in the numerical model. The model is then used to analyze the behaviour of the truss system under realistic and equivalent uniform pressure distributions and to perform an assessment of the use of the tributary area method to calculate the withdrawal force acting on the roof-to-wall connections.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.898-903
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• 2009

Pullorum disease affecting poultry is caused by Salmonella enterica serovar Pullorum and results in severe economic loss every year, especially in countries with a developing poultry industry. The pathogenesis of S. Pullorum is not yet well defined, as the specific virulence factors still need to be identified. Thus, to isolate specific DNA fragments belonging to S. Pullorum, this study used suppression subtractive hybridization. As such, the genome of the S. Pullorum C79-13 strain was subtracted from the genome of Salmonella enterica serovar Gallinarum 9 and Salmonella enterica serovar Enteritidis CMCC(B) 50041, respectively, resulting in the identification of 20 subtracted fragments. A sequence homology analysis then revealed three types of fragment: phage sequences, plasmid sequences, and sequences with an unknown function. As a result, several important virulence-related genes encoding the IpaJ protein, colicin Y, tailspike protein, excisionase, and Rhs protein were identified that may play a role in the pathogenesis of S. Pullorum.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.669-672
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• 2000

This paper presents the methodology which analyze the effect of harmonics in power system. Considering the effect of less-harmonics, economic life and system loss, we have made the comprehensive countermeasure. According to the results of studying harmonics diagnosis and countermeasure, the following problems are pinpointed: protection of power system double investment space of the field. Therefore, in the initial stage, the countermeasure of harmonics trouble are set up. h a results, the following work has been done: $\circled1$ Generation source of harmonics and it's effect into en power system $\circled2$ Review of law related to harmonics, $\circled3$ Countermeasures to reduce the harmonics

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.1130-1135
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• 2009

Avian Influenza is an infectious desease of birds. The infection can cause a wide spectrum of symptoms in birds, ranging from mild illness to a rapidly fatal diseases which might bring a tremendous economic loss to poultry farms[1]. It can also give fatal diseases to human. Therefore it is important to surveil wildbirds that are primary transportation of avian influenza. This report showed a relationship between avian influenza and a habitat of wildbirds using system dynamics, and concluded with suggestion for surveilance.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.49-51
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• 2000

ln this paper, a method by which penalty factors of all generators including slack bus can be directly derived is presented. With a simple re-assignment of angle reference bus to a bus where no generation exists, penalty factors for slack bus is obtained without any physical assumption. While previous Jacobian-based techniques for generator penalty factor calculation have been derived with basis upon reference bus, proposed method are not dependent on reference bus and calculated penalty factors can be substituted directly into the general ELD equation to compute the economic dispatch. Equations for system loss sensitivity, penalty factors and optimal generation allocation are solved simultaneously in normal power flow computation.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.224-228
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• 2004

In these days, as it frequently happens that water level in the river exceeds the design floods due to irregular heavy rainfall, so it is required, first of an, to manage with railroad bridge safely. Because train control criterion under heavy rainfall is still not prepared and automatic flood monitoring system for railroad bridges is not used, worry over invisible economic loss due to train passage delay is in existence. Therefore, it is important to secure the safety and detect the risk like turnover or failure of railroad bridges through systematic disaster prevention system. And the transition from conventional monitoring method to real time monitoring method supported by sensors and communication system with high technology is rapidly needed. This research is on developing the real time flood monitoring system which prevents railroad disasters in advance by detecting continuously the water level of railroad bridge through CCD camera and water level gauge.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.92-97
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• 2003

Roadbed failure due to the rainfall may bring out social and economic demage such as the loss of life and property, the consumption of time and cost for recovery, and the delay of logistics in railway. In this study, the method using Geotextile Container was applied to rehabilitation of the railway roadbed which was failed by rainfall. The real scale tests with the simulated train loading were performed in order to evaluate the dynamic performance at the railway roadbed using Geotextile Container. The results of these tests were compared with unreinforced and reinforced cases with Geotextile Container, respectively. The data gathered by various measurement devices from these real scale tests would be useful to evaluate and understand the roadbed with Geotextile Container. Furthermore, the results of this study would be useful to ensure the workability and to save much time for restoration and to be widely applied to practical use.